I have Southside Machine sub frame connectors (bolt in) and SR Performance (American Muscle) f/r sway bars on my 2K GT convertible. Work great. Really stiffened it up. I also installed the SR Performance front and rear shock tower braces. I used Koni STR.T orange struts/shocks...drives like a go cart...stock springs.
Note 1: the SSM bolt ins are not like the bolt ins one commonly sees...they connect at the K-frame mounting bolts forward and at the lower rear control arm bracket aft. Big bars.
Note 2: I'm not sure SSM still produces the sub frame connectors...you may have to call to see if they have any. Make sure you tell them they are for a convertible.
Happy hunting.